Toyota Prius Prime (2020 year). Owner's manual — part 6

88

2-1. Plug-in hybrid system

EV auto mode (

P. 90)

When a sufficient amount of electricity for EV driving is remaining in
the hybrid battery (traction battery) after charging

*

, the operation

mode can be switched to EV auto mode.
Switching to EV auto mode make powerful driving possible by using
both the gasoline engine and electric motor in a driving condition
that requires large driving force, such as when passing a vehicle on
a highway or driving on a steep slope.

When in EV auto mode, the EV auto mode indicator illuminates.

*

: The amount of remaining charge can be checked on the multi-informa-

tion display etc. (

P. 229)

HV mode
When in HV mode, the vehicle is driven using both the gasoline
engine and electric motor. (

P. 92)

● If electricity needed for EV driving in EV mode or EV auto mode

is not remaining, the operation mode will be automatically
switched to HV mode.

● The operation mode can be switched to HV mode at any timing

by operating the switch to keep electricity for EV driving etc.

*

(

P. 90). Switching to HV mode when driving on a highway or

when driving uphill is recommended in order to conserve battery
power.

When in HV mode, the EV drive mode indicator and EV auto mode indi-
cator turn off.

*

: The EV driving range may reduce even after switching to HV mode.

2

3

89

2-1. Plug-in hybrid system

2

Plug-

in hybrid system

Hybrid battery (traction battery) charge mode (

P. 91)

Electricity generated in the gasoline engine can be charged in the
hybrid battery (traction battery) by switching to the hybrid battery
(traction battery) charge mode when electricity needed for EV driv-
ing is not remaining.

*

● The system may not be able to switch to the hybrid battery (trac-

tion battery) charge mode due to the state of the plug-in hybrid
system. (

P. 91)

● Charging time differs depending on the driving state of the vehi-

cle when driving in hybrid battery (traction battery) charge mode.

When in the hybrid battery (traction battery) charge mode, the hybrid
battery charge mode indicator illuminates.

*

: When in the hybrid battery (traction battery) charge mode, the hybrid

battery can be charged while driving. However, the gasoline engine runs
to charge the battery and fuel consumption becomes higher compared
with driving in HV mode.

4

90

2-1. Plug-in hybrid system

The plug-in hybrid system operation modes can be switched using the
switches.

If there is not enough charge remaining in the hybrid battery (traction bat-
tery) to allow EV driving, EV/EV auto mode will not be selectable.
The hybrid battery (traction battery) charge mode cannot be selected if the
hybrid battery (traction battery) is almost completely charged.

■

Switching the plug-in hybrid system operation modes
Press the EV/HV mode selection switch or EV auto mode switch to
change modes as the following table shows.

When in EV mode, the EV drive mode indicator illuminates.
When in EV auto mode, the EV auto mode indicator illuminates.
When in HV mode, the EV drive mode indicator and EV auto mode indi-
cator turn off.

*

: If there is not enough charge remaining in the hybrid battery (traction bat-

tery) to allow EV driving, EV/EV auto mode will not be selectable.

Plug-in hybrid system operation mode selection switches



EV/HV mode selection switch



EV auto mode switch

Current mode

Switch operated

EV mode

HV mode

EV auto mode

EV auto mode

HV mode

EV mode

HV mode

EV mode

*

EV auto mode

*

91

2-1. Plug-in hybrid system

2

Plug-

in hybrid system

■

Switching to the hybrid battery (traction battery) charge mode
Press and hold the switch.

Take your hand off the switch
once the hybrid battery charge
mode indicator starts to blink.
The hybrid battery charge mode
indicator illuminates when the
switch to hybrid battery (traction
battery) charge mode is com-
plete.
When the hybrid battery (traction battery) is fully charged

*

, the hybrid

battery (traction battery) charge mode is automatically canceled and the
operation mode will be switched to HV mode.
The hybrid battery (traction battery) charge mode will be canceled by
pressing EV/HV mode selection switch or EV auto mode switch.

*

: The maximum charge amount in the hybrid battery (traction battery)

charge mode is approximately 80% of the fully charged capacity for the
charging from an external power source.

■

If the plug-in hybrid system operation mode cannot be changed
In the following situations, the plug-in hybrid system operation mode cannot
be changed even if the EV/HV mode selection switch or EV auto mode switch
is pressed. (In this case, the warning message is displayed on the multi-infor-
mation display when the switch is pressed.)

●

When electricity needed for EV driving is not remaining (when in EV/EV
auto mode)

●

When the traction battery is almost completely charged (hybrid battery [trac-
tion battery] charge mode)

■

When switching from EV mode to another mode using the switch
When the power switch is turned off, operation mode switching is canceled
and the system returns to EV mode the next time the vehicle is started.

■

Hybrid battery (traction battery) charge mode

●

The following may occur to protect the system, etc.
• Cannot switch to hybrid battery (traction battery) charge mode or cannot

cancel it

• Gasoline engine does not start or stops even after switching to hybrid bat-

tery (traction battery) charge mode

●

If a load to the system is large, such as when the power consumption of the
air conditioning system is large or when the temperature of the engine cool-
ant is high, it may take longer time than usual to charge using the hybrid bat-
tery (traction battery) charge mode, or charging to the hybrid battery
(traction battery) may not be performed.

92

2-1. Plug-in hybrid system

■

When in EV/EV auto mode
In EV/EV auto mode, EV driving (driving using only the electric
motor)

*

is possible. However, depending on the situation, EV driv-

ing may be canceled and both gasoline engine and electric motor
are used (

P. 95). Also, if a little electricity is remaining in the

hybrid battery (traction battery), HV mode is automatically selected.
To drive in EV/EV auto mode long, observe the followings.
● Avoid sudden acceleration and sudden deceleration, and be sure

to drive smoothly.
If you repeatedly accelerate, the hybrid battery (traction battery)
charge will deplete quickly. Also, EV driving may be canceled by
rapid acceleration or vehicle speed.

● Restrain your speed as much as possible. The distance that can

be driven in EV/EV auto mode will reduce considerably at high
speeds.

*

: The EV driving range can be checked using the multi-information dis-

play etc. (

P. 212, 228, 235, 252)

■

When in HV mode
The vehicle can be used in the same way as a standard hybrid
vehicle.
In HV mode, controls are primarily carried out as follows in accor-
dance with the driving conditions.
● The gasoline engine stops

*

when the vehicle is stopped.

● During start off, the electric motor (traction motor) drives the vehi-

cle.

● During normal driving, the gasoline engine and electric motor

(traction motor) are controlled effectively, and the vehicle is
driven with optimum fuel efficiency. Also, when necessary, the
electric motor (traction motor) operates as an electrical generator
to charge the hybrid battery (traction battery).

● When the accelerator pedal is depressed heavily, drive force

from both the gasoline engine and the electric motor (traction
motor) is used to accelerate.

*

: When the hybrid battery (traction battery) requires charging or the

engine is warming up, etc., the gasoline engine will not automatically
stop. (

P. 95)

Control when driving in each mode

93

2-1. Plug-in hybrid system

2

Plug-

in hybrid system

■

When braking (regenerative braking)
The electric motor (traction motor) charges the hybrid battery (trac-
tion battery).
The EV driving range can be extended by actively using this regen-
erative braking to store electricity in the hybrid battery (traction bat-
tery).
Moreover, as fuel consumption is also reduced when in HV mode,
the regenerative braking system can be used effectively.

In order to make EV/EV auto
mode available, charge the hybrid
battery (traction battery) from an
external power source before
using the vehicle.

Even if charging the hybrid battery
(traction battery) has not been
completed, the vehicle can be
driven. However, if there is not
enough charge remaining, it is pos-
sible that the vehicle cannot be
driven in EV/EV auto mode or the
EV driving range will become
shorter.

When driving with the gasoline engine stopped, a sound, which
changes in accordance with the driving speed, will be played in order
to warn people nearby of the vehicle’s approach. The sound will stop
when the vehicle speed exceeds approximately 15 mph (25 km/h).

Charging (

P. 110)

Vehicle proximity notification system

94

2-1. Plug-in hybrid system

■

Regenerative braking
In the following situations, kinetic energy is converted to electric energy and
deceleration force can be obtained in conjunction with the recharging of the
hybrid battery (traction battery).

●

The accelerator pedal is released while driving with the shift position in D or
B.

●

The brake pedal is depressed while driving with the shift position in D or B.

■

EV driving range

●

The EV driving range is displayed on the multi-information display etc.
(

P. 212, 228, 235, 252)

●

The EV driving range changes in accordance with the charge status of the
hybrid battery (traction battery), the speed of the vehicle, etc.

●

Even if there is enough charge remaining in the hybrid battery (traction bat-
tery), EV driving may be canceled and both gasoline engine and electric
motor are used depending on the situation. (

P. 95)

■

After EV mode has switched to HV mode due to low hybrid battery (trac-
tion battery) charge
If the hybrid battery (traction battery) is regenerated by driving continuously
down a long slope, the EV driving range etc. will be displayed on the multi-
information display and EV mode will be automatically switched to.
If EV mode is not switched to even though EV driving range is being dis-
played, EV mode can be switched to by pressing the EV/HV mode selection
switch.

■

Refilling fuel
Plug-in hybrid vehicles can be driven using electricity charged from an exter-
nal power source. However, as the gasoline engine is used depending on the
situation even if in EV mode, and the gasoline engine is provided on board as
a power source for driving in HV mode, it is needed to refueling the vehicle.
Check the fuel amount and refill immediately when the fuel level becomes
low. (

P. 368)

95

2-1. Plug-in hybrid system

2

Plug-

in hybrid system

■

Gasoline engine operation in EV/EV auto mode
Even if there is a sufficient amount of electricity remaining in the hybrid bat-
tery (traction battery) and EV driving range (

P. 212, 228, 235, 252) is being

displayed on the multi-information display etc., EV driving (driving using only
the electric motor) may be canceled and both gasoline engine and electric
motor are used depending on the situation (EV driving will be returned to
automatically after EV driving becomes possible again).
EV driving may be canceled automatically in the following circumstances:

●

When vehicle speed is more than approximately 84 mph (135 km/h).

●

When power is needed temporarily, for example when the accelerator pedal
is depressed firmly or when accelerating suddenly.

*

●

When the temperature of the hybrid system is high.
The vehicle has been left in the sun, driven on a hill, driven at high speeds,
etc.

●

When the temperature of the hybrid system is low.

●

When the heater is switched on when the outside temperature is below
about 14°F (-10°C).

●

When the windshield defogger switch is pressed. (

P. 504, 514)

●

When the system determines that the gasoline engine needs to be started.

The gasoline engine may also operate in circumstances other than those
listed above, depending on conditions.

*

: When traveling in the EV auto mode only

■

Conditions in which the gasoline engine may not stop
The gasoline engine starts and stops automatically. However, it may not stop
automatically in the following conditions

*

:

●

During gasoline engine warm-up

●

During hybrid battery (traction battery) charging

●

When the temperature of the hybrid battery (traction battery) is high or low

●

When the windshield defogger switch is pressed. (

P. 504, 514)

*

: Depending on the circumstances, the gasoline engine may also not stop

automatically in situations other than those above.

96

2-1. Plug-in hybrid system

■

If the vehicle is not used for a long time

●

The 12-volt battery may discharge. In this event, charge the 12-volt battery.
(

P. 595)

In order to prevent the hybrid battery (traction battery) from becoming
extremely low in charge, charge the hybrid battery (traction battery) from
external power source or start the hybrid system at least once every 2 or 3
months, and turn the power switch off after the gasoline engine has
stopped automatically. (If the gasoline engine does not start up even after
approximately 10 seconds have passed since the “READY” indicator came
on, the power switch can be turned to off without any further action.)

●

When the vehicle is left with the charging cable connected, the electricity
consumption amount of the 12-volt battery increases due to controls, such
as the system checking, operating. When the charging cable is not needed,
immediately remove it from the vehicle.

■

Sounds and vibrations specific to a hybrid vehicle
There may be no engine sound or vibration even though the vehicle is able to
move with the “READY” indicator is illuminated. For safety, apply the parking
brake and make sure to shift the shift position to P when parked.
The following sounds or vibrations may occur when the hybrid system is
operating and are not a malfunction.

●

Motor sounds may be heard from the engine compartment.

●

Sounds may be heard from the hybrid battery (traction battery) when the
hybrid system starts or stops.

●

Relay operating sounds such as a snap or soft clank will be emitted from the
hybrid battery (traction battery), behind the rear seats, when the hybrid sys-
tem is started or stopped.

●

Sounds from the hybrid system may be heard when the back door is open.

●

Sounds may be heard from the transmission when the gasoline engine
starts or stops, when driving at low speeds, or during idling.

●

Engine sounds may be heard when accelerating sharply.

●

Sounds may be heard due to regenerative braking when the brake pedal is
depressed or as the accelerator pedal is released.

●

Vibration may be felt when the gasoline engine starts or stops.

●

Cooling fan sounds may be heard from the air intake vent. (

P. 99)

■

Vehicle proximity notification system
In the following cases, the vehicle proximity notification system may be diffi-
cult for surrounding people to hear.

●

In very noisy areas

●

In the wind or the rain

Also, as the vehicle proximity notification system is installed on the front of
the vehicle, it may be more difficult to hear from the rear of the vehicle com-
pared to the front.

97

2-1. Plug-in hybrid system

2

Plug-

in hybrid system

■

When “Proximity Notification System Malfunction Visit Your Dealer” is
displayed on the multi-information display
The vehicle proximity notification system may be malfunctioning. Have the
vehicle inspected by your Toyota dealer immediately.

■

Maintenance, repair, recycling, and disposal
Contact your Toyota dealer regarding maintenance, repair, recycling and dis-
posal. Do not dispose of the vehicle yourself.

■

Customization
Setting of the vehicle proximity notification system (volume of sound) can be
changed. (Customizable features:

P. 741)

WARNING

■

When using the hybrid battery (traction battery) charge mode
Observe the following precautions when using the hybrid battery (traction
battery) charge mode while parking.
Failure to do so may lead to death or serious health hazard, as the gasoline
engine operates when in the hybrid battery (traction battery) charge mode.

●

Do not stop the vehicle near flammable materials.

●

Do not use the hybrid battery (traction battery) charge mode in a closed
area where ventilation is insufficient, such as in a garage or area with
snow buildup.

98

2-1. Plug-in hybrid system

Plug-in hybrid system precautions

The illustration is an example for explanation and may differ from the
actual item.

Take care when handling the hybrid system, as it contains a high
voltage system (about 600V at maximum) as well as parts that
become extremely hot when the hybrid system is operating.
Obey the caution labels attached to the vehicle.

Caution label
Charging inlet
Service plug
Air conditioning compressor
Power control unit and DC/DC
converter

Electric motor (traction motor)
High voltage cables (orange)
Battery charger
Hybrid battery (traction bat-
tery)

1
2
3
4
5

6
7
8
9

99

2-1. Plug-in hybrid system

2

Plug-

in hybrid system

There are air intake vents on both
sides of the rear seatback for the
purpose of cooling the hybrid bat-
tery (traction battery). If the vents
are blocked, charging/discharg-
ing of the hybrid battery (traction
battery) may become limited.

When a certain level of impact is detected by the impact sensor, the
emergency shut off system blocks off the high voltage current and
stops the fuel pump to minimize the risk of electrocution and fuel leak-
age. If the emergency shut off system activates, your vehicle will not
restart. To restart the hybrid system, contact your Toyota dealer.

A message is automatically displayed when a malfunction occurs in
the hybrid system or an improper operation is attempted.
If a warning message is shown on
the multi-information display, read
the message and follow the
instructions.

Hybrid battery (traction battery) air vents

Emergency shut off system

Hybrid warning message

100

2-1. Plug-in hybrid system

■

If a warning light comes on, a warning message is displayed or the 12-
volt battery is disconnected
The hybrid system may not start. In that case, try to start the system again. If
the “READY” indicator does not come on, contact your Toyota dealer.

■

Running out of fuel
When the vehicle has run out of fuel and the hybrid system cannot be started,
refuel the vehicle with at least enough gasoline to make the low fuel level
warning light (

P. 664) go off. If there is only a small amount of fuel, the

hybrid system may not be able to start. (The standard amount of fuel is about
2.0 gal. [7.5 L, 1.7 Imp.gal.], when the vehicle is on a level surface. This value
may vary when the vehicle is on a slope. Add extra fuel when the vehicle is
inclined.)

■

Electromagnetic waves

●

High voltage parts and cables on the hybrid vehicles incorporate electro-
magnetic shielding, and therefore emit approximately the same amount of
electromagnetic waves as conventional gasoline powered vehicles or home
electronic appliances.

●

Your vehicle may cause sound interference in some third party-produced
radio parts.

■

Effect of magnetic forces
If objects that generate strong magnetic forces, such as large speakers, are
placed inside the luggage compartment or installed nearby, the generated
magnetic forces may negatively affect the hybrid system.

■

Hybrid battery (traction battery) (lithium-ion battery)
The hybrid battery (traction battery) has a limited service life.
The hybrid battery (traction battery) capacity (the ability to hold a charge)
reduces with time and use in the same way as other rechargeable batteries.
The extent at which capacity reduces changes drastically depending on the
environment (ambient temperature, etc.) and usage conditions, such as how
the vehicle is driven and how the hybrid battery (traction battery) is charged.
This is a natural characteristic of lithium-ion batteries, and is not a malfunc-
tion. Also, even though the distance that can be driven in EV mode decreases
when the hybrid battery (traction battery) capacity reduces, vehicle perfor-
mance does not significantly become worse.
In order to reduce the possibility of the capacity reducing, follow the directions
listed on P. 143, “Capacity reduction of the hybrid battery (traction battery)”.

■

Starting the hybrid system in an extremely cold environment
When the hybrid battery (traction battery) is extremely cold (below approxi-
mately -22

F [-30C]) under the influence of the outside temperature, it may

not be possible to start the hybrid system. In this case, try to start the hybrid
system again after the temperature of the hybrid battery increases due to the
outside temperature increase etc.

101

2-1. Plug-in hybrid system

2

Plug-

in hybrid system

WARNING

■

High voltage precautions
The vehicle has high voltage DC and AC systems as well as a 12-volt sys-
tem. DC and AC high voltage is very dangerous and can cause severe
burns and electric shock that may result in death or serious injury.

●

Never touch, disassemble, remove or replace the high voltage parts,
cables or their connectors.

●

The hybrid system will become hot after starting as the system uses high
voltage. Be careful of both the high voltage and the high temperature, and
always obey the caution labels attached to the vehicle.

●

Never try to open the service plug
access hole located in the luggage
compartment. The service plug is used
only when the vehicle is serviced and is
subject to high voltage.

102

2-1. Plug-in hybrid system

WARNING

■

Road accident cautions
Observe the following precautions to reduce the risk of death or serious
injury:

●

Pull your vehicle off the road, apply the parking brake, shift the shift posi-
tion to P, and turn the hybrid system off.

●

Do not touch the high voltage parts, cables and connectors.

●

If electric wires are exposed inside or outside your vehicle, an electric
shock may occur. Never touch exposed electric wires.

●

Do not touch the battery if liquid is leaking from or adhering to it.
If electrolyte (carbonic-based organic electrolyte) from the hybrid battery
(traction battery) comes into contact with the eyes or skin, it could cause
blindness or skin wounds. In the unlikely event that it comes into contact
with the eyes or skin, wash it off immediately with a large amount of water,
and seek immediate medical attention.

●

If electrolyte is leaking from the hybrid battery (traction battery), do not
approach the vehicle.
Even in the unlikely event that the hybrid battery (traction battery) is dam-
aged, the internal construction of the battery will prevent a large amount of
electrolyte from leaking out. However, any electrolyte that does leak out
will give off a vapor. This vapor is an irritant to skin and eyes and could
cause acute poisoning if inhaled.

●

Do not bring burning or high-temperature items close to the electrolyte.
The electrolyte may ignite and cause a fire.

●

If a fire occurs in the hybrid vehicle, leave the vehicle as soon as possible.
Never use a fire extinguisher that is not meant for electric fires. Using even
a small amount of water may be dangerous.

●

If your vehicle needs to be towed, do so with front wheels raised. If the
wheels connected to the electric motor (traction motor) are on the ground
when towing, the motor may continue to generate electricity. This may
cause a fire. (

P. 655)

●

Carefully inspect the ground under the vehicle. If you find that liquid has
leaked onto the ground, the fuel system may have been damaged. Leave
the vehicle as soon as possible.

103

2-1. Plug-in hybrid system

2

Plug-

in hybrid system

WARNING

■

Hybrid battery (traction battery)

●

Your vehicle contains a sealed lithium-ion battery.

●

Never resell, hand over or modify the hybrid battery. To prevent accidents,
hybrid batteries that have been removed from a disposed vehicle are col-
lected through Toyota dealer. Do not dispose of the battery yourself.
Unless the battery is properly collected, the following may occur, resulting
in death or serious injury:
• The hybrid battery may be illegally disposed of or dumped, and it is haz-

ardous to the environment or someone may touch a high voltage part,
resulting in an electric shock.

• The hybrid battery is intended to be used exclusively with your hybrid

vehicle. If the hybrid battery is used outside of your vehicle or modified
in any way, accidents such as electric shock, heat generation, smoke
generation, an explosion and electrolyte leakage may occur.
When reselling or handing over your vehicle, the possibility of an acci-
dent is extremely high because the person receiving the vehicle may
not be aware of these dangers.

●

If your vehicle is disposed of without the hybrid battery having been
removed, there is a danger of serious electric shock if high voltage parts,
cables and their connectors are touched. In the event that your vehicle
must be disposed of, the hybrid battery must be disposed of by your Toy-
ota dealer or a qualified service shop. If the hybrid battery is not disposed
of properly, it may cause electric shock that can result in death or serious
injury.